A routine traffic stop near Havre de Grace Tuesday led to three arrests and the seizure of more than 2 kilograms of cocaine powder worth an estimated $210,500, a 1991 Acura Integra and $44,500, authorities said yesterday.

State police and undercover officers from the Harford County Joint Narcotics Task Force also seized a handgun, said Cpl. John Wilhelm of the John F. Kennedy barracks in Perryville.

The traffic stop in Harford County prompted troopers to arrest a New Jersey motorist and triggered an undercover sting that led to two more arrests in Baltimore County Tuesday night, the corporal said.

The motorist, Miguel Eduardo Velez, 41, of Jersey City, N.J., was stopped for speeding southbound on Interstate 95 just south of Havre de Grace about 2:30 p.m. Tuesday, police said. Tfc. John Appleby obtained the driver's consent to search Mr. Velez's Acura and found 2.13 kilograms of cocaine, about 4.7 pounds, hidden in the vehicle's rear bumper, according to police.

Mr. Velez was arrested on charges of possession, possession with intent to distribute and smuggling cocaine.

A woman passenger in the Acura was initially detained, then released, Corporal Wilhelm said.

About 9 p.m. Tuesday, task force agents arrested two Baltimore men off Perring Parkway near Parkville after an undercover drug sale that was connected to the cocaine seized from the Acura, the corporal said.

The agents charged Ralph Quahn Purnell, 21, and Leroy Durham Jr., 21, with cocaine possession and possession with intent to distribute cocaine.

A pistol found in their 1994 Honda Civic was confiscated, Corporal Wilhelm said.

Mr. Velez was being held at the Harford County Detention Center in Bel Air on $1 million bond, a jail spokesman said yesterday.

Mr. Purnell and Mr. Durham were held at the Baltimore County Detention Center in Towson, each on $250,000 bond, an official there said.